Self-cleaning filter



De@ 26, '1944. w. Jon-:1. 2,366,112

SELLCLEANING FILTER Filed Nov. 21, 1941 'o Intil i I AiTonNgvsf.-

` Patented Dec. 26, 1944 UNITED'- STATES PATENT oFFlCE -srLl-oLEANnvdFILTER William Jokel, Brooklyn, N.,Y. Application November 21, 1941,serial Nofilasez 1 claim.

In the draw-ing affixed to this specification and i forming part thereofan embodiment of my new lter is illustrated diagrammatically by way ofexample.

n the drawing:

Fig. 1 is a vertical axial section of filter, andv Fig. 2 shows adetail.

Referring to the drawing, 22 is the inlet pipe and 2 the outlet pipe ofa'filtering device according to this invention inserted in a liquidsupply vpipe of a forced feed lubricating system or x the like. I8 is afilter casing inserted between the inlet and outlet and 24 is a hollowpiston fitting jin the casingr I8 for free axial movement, while y 31 isa coil spring ,inserted between the casing my new bottom andthe bottomof the hollow piston. 36\

is a strainer in the piston, formed bywire netfting, perforated sheetmetal or the like, which carries the filtering material 35, preferablyconsisting of small globules of a light metal, plastic or other 1iforated co r of the hollow piston 24, which thus constitutes a vesselwith a perforated' cover.

The casing I8 receives its normal oil supply through an intake valve I9connected through a branch pipe 20 with the main oil supply pipe 2 I.Another branch pipe 22 leads from the main supply pipe to a port 23 nearthe casing bottom.

tending downward and partly surrounding the port 23, ends near thecasing bottom at2'l (Fig. 2). Another port 2,8 in the top part of thepiston Wall registers'with the waste pipe 29 in the casing wall onlywhile the piston is lowered'into its t weight material, and 34 is theperextreme position. The piston byl meansof an axially extending rod 30controls the intake valve body. 3| and exhaust valve body 32 at thecasing bottom, which valve bodies alternately open and Vshut off theintake valve I9 andexhaust valve 33.

In the operation of this device the liquid to be ltered,` entering at2l,normally flows through f branch pipe '20, the open valve I9 andthe per#forated top 34 into the top part o f piston `24 and after passingthroughthe layer of `35 ofnltering 36, exhaust port 25, curved vgroove 216 andexhaust valve 33. f

When the lter is clogged and the pressure in the casing risesaccordingly, the piston 24 being lowered againstvthe action of thespring 31 shifts its exhaust port 25 into' register with the opening 23of branch pipe 22, at the same time bringing the port 28 into registerwith the waste pipe 29, while valve bodyV 3| shuts off the flow ofliquidthrough branch pipe 20 and valve body 32 closes the exhaust. I'heuncleaned oil now enters the bottom part of the piston :and passes frombelow through the perforated bottom 36y and the filtering material 35and port 28 into the Waste pipe. The reversal of the iiow of the liquidcauses the layer of filtering material to be loosened by lifting thefiltering bodies and the impurities in the filter to be carried away. Assoon las the filter has become permeable again for the normal flow thespring 31 is able to lift the piston 24' into its normal position,'thereby also opening the valves I9 and 33, while shutting on connectionbetween the branch pipe 22 and the interior of the pistonV and restoringcommunication between the bottom part of the piston and of the casing.

I wish it tobe understood that- I do not devsire to be limited to theexact details of co'nhollow piston arranged in said casing forreciprocating movement between said main intake. port and said mainexhaust port, a` strainer exI tending across the cavity in said piston,a body of loose ltering material located on the side of said strainerfacing said main intake port, resilient means arranged to act on saidpiston in axial direction, means controlled by said piston foralternately shuttingoi and reestablishing the flow of liquid throughsaid main intake and K' exhaust ports, two auxiliary ports in theycasing wall on different sides of the strainer' plane and two auxiliary.ports in the piston wall, each auxil- ,iary piston port being axiallyaligned with and so spaced from an auxiliary casing port,1that inone endposition ,of the piston only one auxiliary piston port registers withthe corresponding auxiliary casing port, and an auxiliary liquid supplyconduit connected with the auxiliary casi ing port arranged on the samesideof the strainer 'plane as said mainliquid'exhaust port.

material escapes through the perforated `bottom t wnrrAMJoKEL

